Success has been found in other THz systems, such as solid-state and molecular systems [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, metasurfaces [8]}, quantum gases [7]} and more recently air plasma [10]}. The use of topological systems as a robust platform for lasing is also developing as an exciting field, most notably in the mid-infrared  [11]}, [12]}, [13]}, [14]}, [15]}, [16]}, [17]}, [18]}, [19]}, [20]}, [21]}, although work has been done on THz lasers using 2D topological insulator quantum dots (TIQDs), requiring electron injection and an IR pump [22]}.
